Field of the Invention
The invention relates to an arrangement for the partial release of a debug interface of a programmable hardware component.
Description of the Background Art
In addition to a dedicated configuration interface for the programming of the hardware component, programmable hardware components such as processors, FPGAs and CPLDs often feature a debug interface which is mainly provided for the debugging of the logic programmed on the hardware interface. Just like the configuration interface, this logic is also suitable for programming the hardware component.
In some application scenarios, the option of programming the hardware component via the debug interface can be problematic, for example, if a second programmable hardware component is linked to the configuration interface of a first programmable hardware component in such a way that the first programmable hardware component is programmable by a user via a second programmable hardware component, whereby the second programmable hardware component only partially allows the user freedom for programming the first programmable hardware component. This can occur, for example, in such a way that the second programmable hardware component programs an obligatory interface logic on the first programmable hardware component in addition to the logic programmed by the user, which supplies logical mechanisms for the data exchange with the hardware environment of the first programmable hardware component and prevents the user from damaging the first programmable hardware component or its hardware environment through faulty programming. In this case, the complete release of the debug interface of the first programmable hardware component allows the user to program a logic on the first programmable hardware component without the provided safety logic.
The patent specification U.S. Pat. No. 7,971,051 describes an arrangement for the automatic reprogramming of an FPGA via the monitoring of a signal emitted by the FPGA when programming of the FPGA is faulty or inadmissible.